In the settable slip clutches of the prior art, e.g. according to the Swedish patent application 8602529-3, it has been found that there is a hammering friction torque, due to the balls returning to their inactive positions each time the recesses in the driving shaft and the chambers in the driven shaft come opposite each other. During rotation the balls will then engage against the chamber walls as well as the surface of the recesses. The appreciable frictional torque results in large heat generation in the clutch and heavy wear on the balls.
Another disadvantage of this kind of clutch in the prior art is that it slips unintentionally when the rotational direction is reversed, due to the torque which then occurs exceeding the value set with the aid of the spring bias.